Mars rovers roving again, for now

Skies clear, but dust poses new threat

Giant dust storms that have pinned the Mars rovers down for the last six weeks are beginning to lift, allowing the two explorers to restart their slow crawl over the red planet's surface.

The storms have blotted out the light from the sun, leaving the craft virtually powerless as their solar panels lay in shadow. When the severity of the storms became clear, mission managers elected to have the craft hibernate to ride it out. Then, earlier this week, NASA said the craft could resume their exploration.

Although the skies are now clearer, it will also take some time for the skies to clear properly, as project scientist Bruce Banerdt explains: "The clearing could take months. There is a lot of very fine material suspended high in the atmosphere."

As this dust settles it poses a new threat to the rovers: the particles are landing on the Rovers' solar panels, reducing their electricity supply. And although a kind wind shifted some dust from Opportunity's panels earlier this week, they are not out of the woods yet.

Mission managers directed the rover to head for the slope of the Victoria crater. This will mean the solar panels will be pointing directly at the sun, allowing the little craft to maximise its photon collection.

The dust is causing other problems for Opportunity's twin, Spirit: very fine particles have landed on the lens of the microscopic imager, slightly reducing the quality of the data it can collect. NASA boffins are trying to work out how to shift the build-up.

Both rovers are now generating around 300 watt hours from their panels. This is more than twice as much as five weeks ago, but less than half the output prior to the storm. ®